Dual-rotation test drive



April 24, 1945. T. c. JAcKsoN DUAL ROTATION TEST DRIVE 3 Sheets-Sheet 1 y V y c c. M

April24, 1945. T. C. JACKSON 2,374,207

DUAL RoTATIoN TEST DRIVE Filed NOV. 18, 1943 5 Sheets-SheetI 2 vus/vm@ TOM C. UAC/SON pr 24, 945. l T. c. JACKSON DUAL ROTATION TEST DRIVE Filed Nov. 18, 1943 3 Sheets-Sheet 3 TOM UAC/(SON YW du@ Patented Apr. 24, 1945 unimo sfr/Ares TENT lorries Granted under .the .act of .March `s, 1883, ,as

vamended ADriL30, 192853700. G5757) I "The invention described hereiwmaybe manuactured and `used-'by or *for 'Government for governmental purposes, without theA payment to me ofanyroyalty thereon.

This invention relates to a mechanicalfdevice forfconnecting the two concentric shafts 'of a dual rotation engine to two vdynarnorneters lor similar "torque measuring i instrumentalities lfor the purpose -of --making -engine tests, the two dyna-rnometers,v being in axial-alignment with the engi-ne rslfiz-iits and witheach other. The` two hengine shafts may rotate oppositely or in^the-same direction.

'The objects-'of this inventioneare, rst, to'pro- Vide-a system Iwhich'niaybeadaptedto-all dual rotationengines andm dynamometer designs ofY the hollow 'rotor type; second, to provide a direct means of 'connection between Vengine-and dynainometer which Ywill afford -an individual, 4,yet simultaneous calibration lof each engine shaft. Thisesystem will avoid the use of geartrains or any `such-mechanism which willintroduce loss ofpower transmitteddue to'friction anda design Whichwill not present complicated assembly, disassemblyv andA maintenance problems.

-Thisinvention, :taken collectively or in anyof itscomponent parts; is notto be associated with the design Aor claims of any particular dynamometer or Vengine arrangement. .It is` aseparate and independent arrangement and isto be considered as 'atransmission j linkage' between engines and dynamometers incorporating the principles of dual rotation.

LIhe objects of this invention havebeenattained by ,the mechanism illustratedin'theiaccompanyingjdrawings, in which:

'LFig ll. Fig. .1a Yand Fig. ylb..are, thethreerparts of La vertical axial section` through4 a `preferred embodiment of the `inventionas it .will` Iwear when,asse1nbled and connected for testing van engine having two shafts 1sucl'ras areprovided for a iolualrrotation. propeller .and I .,Ei'gs.. 2,iand..3 `are. detailv views ofiA two of thelocking means .employed to @maintain propereassembly of someiofrthenparts.

. Referring .i now more particularlyv to the` left or engine end f of the drawings,v an -engine- Ii);` has -a rei-atively'long hollow propellerzshaft. |'2`extending laterallyauand a second larger butshorter shaft Larconcentrically surrounding the rst. :The first ori-longer shaftA i 2 may ybe Vfreferredy to; asthe-.outboardfshait, andthe-,seconder shorterv shaft i4, the inboard` shaft. :In-applying the ltesting apparatus, .which `is the fsubject fof 1 this vreinvention,

to .an engine, the propellers,.arefneoessarily@tor the time omitted. fromshaf-tsviZ and E Ul,v and :are replaced'respectively with adapters rl" t6 ian'd f i 8.

.Adapters iIB and 118. "have internal contours which: are substantially Aduplicative lof 'the I`outboard :and -inboard --propeller hubs respectively` Inasmuch,` however, Aas a number f of i different engines are to be tested by means of theapparatus herein disclosed; resulting-iny a'considerable `vnumberof shaft combinations; there vmustnecessar-ly be `a Ydiierent adapter for -eachf-diierentsizef of outboard and-'each different-size of `inboard shaft. 'Adaptersfl and IB'are'itted totheparticular shaft combination s-hown, and are-drivably affixed thereto'in-the same manner as the hubs of the prope'zllersl whichVv are subsequently 'tobe attached tothe shafts. g

The inboardadapter i8 has internal splinestZG tted to the-external splines of shaft M, an'd is clamped betweena-rearfcone 22'and a front cone 2li-bythe clamping nut-26,` the nut beinglocked against :rotation relative 'to the inboardh adapter' bya split lockingringj, which carries a keyg3 extendingradially, inward from the ring (see Fig. 2),'.the key passing through Vone of a series of slots inl the end of the vnut26 into one oa series ofsslots in ltheend of the inboard vshaft Ill.

The Isplit lockingring is ,sprungintoaaannularvgroove in .the-.bore of theadapter ,'loto secureit against axial displacement. An antifrictionbearing'.32' has.itsiouter racegtted to the boreof the adapter L8 -.anddtsinner.racentted to the ,external ,diameter `.of `the outboard `shaft l2. Theinner race .ofbearing 32 is'clamped betweenspacing `washers 34 and 6. againsta .shouldery portion 38on the -outboard shaft; I2. l

The outboardladapter I 6 hasinternal splines 4.9 tted to i the.l external; splines` Oishaft i2,` and is clamped betweena rear cone=42 `and a front cone JM by the V-clampingl nut T46, i the nut ibeing locked against; rotation; relative ,tof the adapter; 1,6 by. a split locking,` ringx48 whicngcarries a-keyril extending. radially both outwardand inwardf from the ring iseeFigx) the finwardlyfextendingportion of the :key` passing :throughone oiga series of fslots vin itheend Aofthe 1;nutg46, -ancilathe'out- Wardly -2 extending portion` of I the key passing through one-of a series.` of; slots in the. end ofthe the adapter I6 to the outboard shaft I2. Clamping nuts 26 and 46 are both of the conventional type which are provided externally with annular ribs 21 and 41 which extend into internal annular grooves in the cones, whereby the nuts are capable of withdrawing the front cones 24 and 44 as well as forcing them inward into place.

The extreme outer diameter of the adapters I6 and I8 are provided respectively with splined por,- tions 2 and 54. It is noted that While the inner configuration of the several adapters will vary in accordance with the engine shafts upon which they are to be used, the splined portions 54 of all inboard adapters are identical and the splined portions 52 of all outboard adapters are identical.

. Two concentric torque tubes 56 and 58 are provided for transmitting the torque of the inboard and outboard shafts respectively to the front and rear dynamorneters. A large sleeve 60 drivably connects the inboard adapter |8 to the outer torque tube 56. The engine end of the sleeve 60 is internally splined to t slidably over the external splines 54 of the inboard adapter I8, the outer end of the sleeve being of smooth bore adapted to fit slidably over the enlarged end 62 of the outer torque tube 56. Circumferentially spaced screws 64 drivably connect the sleeve 60 and tube 62.

The inner torque tube 58 is reduced in diameter at the engine end, the reduced end being provided externally with splines 66. A hanged hub 68 has internal splines which t slidably over the splines 66, the hub being clamped between a rear cone 10 and a front cone 12 by the clamp nut 14. A locking bolt 16 is inserted through one of a-series of holes 18 in the end of the tube, and through one of a series of somewhat elongated openings in the nut. A spacing collar 80 is clamped between the rear cone 10 and a shoulder 82 on the inner torque tube 58.

A short sleeve 84 is concentrically held on the engine epd of the hub by the cap screws 86, the engine end of the sleeve 84 being provided with internal splines which t slidably over the splines 52 on the outboard adapterV I6. Lubricant seals 88 and 90 are held respectively in seal housings 92 and 94 and are secured to the engine ends of the sleeves 84 and 60 by cap screws 96 and 98.

Referring now to the right hand or dynamometer end of the drawings, the inner torque tube 58 is provided with a tapered rear end portion |00 to which the internally tapered hub of the flange I 02 is tted. The hub and the tapered end portion of the shaft are drivably connected by means of keys |64, the hub being pressed into place on the taper by the nut |06. A locking bolt |08 is inserted in one of a series of radial holes in the end of the tube and extended also through one of the series of elongated slots in the nut, whereby the nut is secured in its adjusted position. The ange |02 is held by cap screws ||0 to the front face of the rear dynamometer coupling ||2, the coupling being fastened on the front end of the hollow shaft |`|4 o the rear dynamometer rotor by the nut I I6.

The rear end of the outer torque tube 56 is enlarged as at I I8 and the hub of the flange |20 is slidably fitted thereover. Cap screws |22 drivably connect the enlarged portion ||8 and the flange |20. The flange is held by cap screws |24 to the front face of the front dynamorneter coupling |26, the coupling being fastened to the front end of the hollow shaft |28 of the front dynamometer rotor by the nut |30.

In order to prevent whip at the mid portion of the inner torque tube 58, an antifriction alignment bearing |32 is mounted with its outer race concentrically held in the enlarged portion ||8 of the outer torque tube 56 by a bearing retainer |34 which is held against the outer race by cap screws |36, the inner race being mounted on an externally tapered split sleeve |38 which is drawn by a nut |40 into the tapered bore of the inner race, which coincidentally fixes the inner race to the split sleeve |38 and the split sleeve |38 to the torque tube 58. A lock washer |42 maintains the nut inthe adjusted position. An oil retainer |44 is held by cap screws |46 against a shoulder in the bore of the enlarged end ||8 of the outer torque tube for retaining the bearing Ilubricant at the engine end. The bearing retainer |34 has an oil seal portion |48 which seals against escape of bearing lubricant at the dynamometer end. A filler plug is provided for entry of bearing lubricant. An overflow plug |52 is provided and should be removed when I lling the bearing space with lubricant.

Preparation for testing an engine arranged for dual-rotation propellers is preferably made as follows:

The rear dynamometer may first be moved backward away from the front dynarnometer to afford working room for making necessary connections thereto. Couplings ||2 and |26 are attached to the forwardends of the dynamometer rotor shafts ||4 and `|28 respectively bythe nuts ||6 and |30.

The inner torque tube 58 is now fed through the hollow rotor shaft |28 of the front dynamom eter until its tapered end |00 extends into the space between the two dynamometers. The keys |04 are next put in place and the flange |02 is drawn up n the keys and the taper |00 by the nut |06, the nut being then locked by a bolt |08.

The rear dynamometer may now be moved forward and secured in position on the bed plate, then the flange |02 secured to the rear dynamometer coupling I2 by the cap -screws H0.

Split sleeve |38 with its alignment bearing |32, nut l|40 and lock washer |42` are now correctly located on the inner torque tube 58 and fastened with the nut |40. The oil retainer |44 is secured in the enlarged rear end ||8 of the outer torque tube 56 by means of the cap screws |46. The outer torque tube 56 is then concentrically moved over the inner torque tube 58 from the engine end untilthe outer race of the bearing 32 is seated in its recess in the enlarged rear end I8. Bearing retainer |34 with its oil seal portion |48 is now fastened in place with the cap screws |36.

Flange |20 is now brought into position over the enlarged end I8 to the dynamometer coupling |26, after which the nange is secured to the enlarged end 8 by means of the cap screws |22 and to the dyanamorneter coupling by means of the cap screws |24. This will complete the dynamometer end connections.

In making the engine end connections, the spacing collar 80 and rear cone 1 are slipped over the inner torque tube 58 until stopped by the shoulder 82. The cap screws 8B are inserted in the holes in the anged hub 68 after which the flanged hub 68 is put into place with the internal splines of the hub fitting into the external splines 66 of the inner torque tube. The front cone 12 is then put on and drawn up by the nut 14, the nut being locked with a bolt 16. The short sleeve 84 may now be concentrically secured to the flanged end of the hub 68 by the cap screws 86.

The large sleeve should now be moved completely over the enlarged end 62 of the outer torque tube 56, the smooth bored end of the sleeve, having the radial cap screw holes, going over rst. The sleeve 60 may be temporarily left hanging loosely on the outer torque tube 56 preferably near the front end of the iiange I20.

The testing apparatus is now ready to be con- I nected to the engine, but before bringing the engine up into position, the adapters which replace the propellers during test should be-installed on the engine shafts, the procedure preferably being to slip the oil seal 90 and its housing 94 over the inboard adapter I8, then place over the inboard engine shaft I4, the cone 22, then the inboard adapter I8 with its internal splines 20 in mesh with the external splines of the shaft, then the front cone 24 and nut 26, the nut being drawn up and locked with the special locking ring 28.

I'he spacing Washer 34 and bearing 32 are put on the inboard shaft I2, and since both `the inner and the outer races of the bearing are press fitted to their nal positions, the bearing should be carefully driven home by applying appropriate force to the inner and outer races coincidentally. The washer 36 and cone 42 are slipped over the outboard engine shaft I2, then the oil seal 88 and its housing 92 slipped over the outboard adapter I6, then the adapter I6 put on with its internal splines 40 meshed with the external splines of the shaft, then the front cone 44 put on and drawn up by the nut 46 and locked with the special locking ring 48.

The engine with its adapters thus assembled thereon may now be moved up into position for nal coupling, the external splines 52 of the outboard adapter I6 being entered a predetermined measurable distance into the internal splines in the short sleeve 84 when the engine has reached its correct position. Fastening the oil seal housing 92 by means of the cap screws 96 completes connection of the outboard engine shaft to the rear dynamometer.

Lastly the large sleeve 60 is brought forward from its position on the outer torque tube 56, over the enlarged end 62 until the internal splines in the front end mesh with the external splines 54 on the inboard adapter and the radial holes in the sleeve 60 and in the enlarged end 62 of the outer torque tube 56 are aligned. Drivably connecting the sleeve 60 and the part 62 with the cap screws 64, and fastening the oil seal housing 94 to the front end of the sleeve 6D by means of the cap screws 98 completes the connections for testing the engine. Lubrication of the alignment bearing |32 is accomplished ,by first removing the overow plug |52, then placing the oil filler plug |50 on topcenter and supplying lubricant until it runs out at the overflow opening.

Having described by invention, I claim:

For connecting a dual rotation engine having coaxial inboard and outboard propeller shafts to a front and a rear dynamometer having rotor shafts in axial alignment with each other and with said propeller shafts, the rotor shaft of the front dynamometer being hollow, the improved connecting apparatus which 'comprises an outer torque tube having its rearward end adapted for drivable attachment to the hollow shaft of the front dynamometer and its forward end adapted to be in a position near the outer end of the outboard propeller shaft, an inner torque tube having its rearward end adapted for drivable attachment to the shaft of the rear dynamometer, its mid portion adapted to extend through the hollow shaft of the front dynamometer and its forward end extending through the forward end of the outer torque tube, an antifriction bearing ,assembly concentrically supported on the inner torque tube and in the outer torque tube at the forward en'd of the front dynamometer shaft, an outer connecting sleeve having its rearward end drivably connected to the forward end of the outer torque tube and its forward end adapted to concentrically surround the inboard propeller shaft, an inner connecting sleeve having its rearward end drivably connected to the forward end of the inner torque tube and its forward end adapted to concentrically surround the outboard propeller shaft, said outer connecting sleeve being internally splined at the forward end, an outboard adapter externally and internally shaped to respectively make driving connection between the inner connecting sleeve and the outboard propeller shaft, and an inboard adapter externally splined and internally shaped to respectively make driving conneotion between the outer connecting sleeve andthe inboard propeller shaft, and driving means between the forward end of the outer torque tube and the rearward end of the outer connecting sleeve being removable from the outside, whereby the outer connecting sleeve is axially slidable to uncover the inner connecting sleeve.

TOM C. JACKSON. 

